- Kauf, Adam C.W.
- Graduate Program:
- Animal Science
- Doctor of Philosophy
- Document Type:
- Date of Defense:
- June 16, 2004
- Committee Members:
- Ronald Scott Kensinger, Committee Chair/Co-Chair
Daniel R Hagen, Committee Member
Lester C Griel Jr., Committee Member
Kenneth Kephart, Committee Member
- sow milk composition
- Mastitis is a common contributing factor to the relatively high pre-weaning mortality rate and suboptimal sow-reared piglet growth performance experienced in pork production. An endotoxin challenge model of mastitis was used to determine its effects on sow milk composition, milk yield, and the growth of nursing piglets. Caseins (beta-casein in particular), lactoferrin, and immunoglobulins, as determined by SDS-PAGE and ELISA, were high in colostrum, and levels decreased to mature levels by about day four of a normal lactation. As mammary secretions changed from colostrum to milk, decreasing levels of chloride and albumin provided evidence for the closure of tight junctions by about day four of a normal lactation. Following endotoxin infusion to induce mammary inflammation, sow rectal temperatures peaked at 1.1-1.7 degrees C above baseline by five hours post-infusion, and gradually recovered within 12-24 h. Milk TNF-alpha was increased 30-fold by five hours post-infusion (serum TNF-alpha appeared to increase); both recovered by 12 h. Milk total protein (20 %), albumin (44 %), and chloride (two-fold) were increased, and milk alpha s- and beta-casein (45 %) were decreased post-infusion; milk protein composition was altered for at least 48-60 h. It did not appear that lactoferrin in milk responded to intramammary endotoxin infusion. Hourly milk yields of infused mammary glands were decreased 16-31 % relative to control glands and the ADG of piglets nursing infused glands were decreased 44-74 % relative to littermates nursing control glands on the day of endotoxin infusion. The ADG of piglets nursing infused glands remained decreased relative to littermates nursing control glands for at least five days post-infusion. The apparent conversion of milk to live weight gain of pigs nursing infused glands was decreased relative to those nursing control glands. Intramammary endotoxin infusion in the sow alters milk composition and depresses piglet growth performance for at least three to five days after the resolution of clinical signs of mammary inflammation. This research demonstrates the impact of a mild inflammatory episode on pig production, and highlights the need for supplemental feeding of piglets at risk.